Volume 5 Issue 1, January 2019

Magnoliid genomes provide novel insight into early angiosperm evolution, showing how whole-genome duplication and proliferation of transposable elements have shaped these genomes. Now, two papers giving differing views of early angiosperm phylogeny, raise questions about the relationships among eudicots, monocots and magnoliids.

Sporopollenin, which encapsulates gametes in spore and pollen grains, is probably the most chemically inert biopolymer. This inertness is essential for gamete protection, but also hinders the elucidation of sporopollenin molecular structure. Now, the macromolecular network forming sporopollenin is described in unprecedented detail.

The vacuole is a plant’s major phosphate (Pi) pool. Cellular Pi homeostasis highly depends on shuttling Pi between vacuoles and the cytosol. Glycerol 3-phosphate transporter types have now been identified as tonoplast-localized vacuolar Pi efflux transporters, integrating vacuolar Pi transport systems in plants.

A Perspective summarizes advances in the research of plant diversity, and discusses how big data resources and new technologies, such as analytical and integrating tools, are revolutionizing our views of plant diversification and guiding conservation.

The engineered Streptococcus pyogenes Cas9 variant SpCas9-NGv1, known to recognize relaxed NG protospacer adjacent motifs (PAMs) in human cells, can also mediate targeted mutagenesis with NG PAMs in rice and Arabidopsis. When fused with cytidine deaminase, it mediates C-to-T substitutions.

A high-quality reference genome for the plant Liriodendron chinense places magnoliids as sister to the clade consisting of eudicots and monocots. Population genomic analyses unravel the evolution of two distinct species in the genus Liriodendron.

Detection of extrachromosomal linear DNAs in crops with large and transposon-rich genomes is challenging. Now an approach named ALE-sequencing is developed, allowing for the sensitive detection of active LTR retrotransposons in rice and tomato.

Photosynthetic organisms minimize potential harm from excess light by protection mechanisms collectively referred to as non-photochemical quenching. Two proteins involved in quenching, DAMAGED DNA-BINDING 1 and DE-ETIOLATED 1, are part of a complex containing CULLIN 4.

A distinct feature of pollen gains is their resistant outer wall, called the exine, which is mainly composed of sporopollenin, the toughest biopolymer known to date despite an unknown detailed structure. Now, a structural model of pine sporopollenin is revealed by the application of new degradation chemistry and solid-state NMR spectroscopy.

Rubber tree plantations have been displacing tropical forests in Southeast Asia, linked to global rubber prices. Forest-to-plantation conversion in Cambodia is correlated with shifts in rubber prices, with a time lag of under a year, showing the link between global commodity markets and deforestation in developing nations.

A sunflower pan-genome determined by sequencing about 500 accessions, including wild, landrace and cultivated lines, showed that introgression from the wild species has profoundly shaped the cultivar gene pool and contributed disease resistance genes.

A high-quality reference genome of the stout camphor tree reveals its genome evolution and supports that magnoliid and eudicot lineages share more common ancestry relative to monocots.

A study examined transcriptome dynamics of Arabidopsis halleri weekly for two years and bihourly for the four equinoxes/solstices, revealing that the change of temperature rather than day length dominantly defines the seasonal transcriptome oscillations.

Phosphorus is one of the essential nutrients for all living organisms. Plants and fungi store phosphate in their vacuoles. Multiple plant influx transporters have been reported to import phosphate to the vacuoles. Now, two new phosphate efflux transporters are shown to be important for phosphate export from the vacuole in rice and probably other land plants.

The plant vacuole plays important roles in regulating growth and development. Now, the vacuole in Arabidopsis root cells is presented at nanometre resolution by 3D whole-cell tomography, suggesting a cellular mechanism for plant vacuole formation.

This study characterized the unique protein subunit composition and structure of Arabidopsis mitochondrial ribosomes using biochemical assays and cryo-electron microscopy. Ten subunits are pentatricopeptide (PPR) proteins, among which rPPR1 functions as a translation factor.